# NTSB DFW05CA109: Robinson R22, N422SH, Bandera, TX, April 27, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 27, 2005, 08:31 local (13:31 UTC) - Place: Bandera, TX - Coordinates: 29.976667, -99.085556 - Nearby events: https://openairdocs.org/map.md?lat=29.9767&lon=-99.0856&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report July 7, 2005 - Report: Approved by Office Director - Parties: San Antonio, Texas - NTSB case key (mKey): 61365 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW05CA109 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61365/pdf - Page: https://openairdocs.org/ntsb/DFW05CA109 ## Probable cause The pilot's loss of control while hovering after encountering settling with power. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, hover - settling with power - encountered, pilot in command (cause) - In flight collision with terrain/water, hover - terrain condition - water ## Analysis The 2,216-hour pilot refueled at a private ranch and departed with a passenger to "begin a process of herding some exotic animals across an earthen dam to an open area for capture." One particular trophy exotic that they were trying to capture began to swim in a creek below, and "it was obvious that the animal was struggling to cross." The pilot then began to hover beside the animal to herd it out of the water and towards the bank. At this point, "the aircraft began to settle with power at a height of approximately six feet above the water." The pilot "applied forward cyclic and right pedal, along with a lower collective setting. The skid gear then settled into the water with forward motion, and the main rotors contacted the water." The helicopter sank in approximately six feet of water. ## Factual narrative On April 27, 2005, approximately 0831 central daylight time, a Robinson R22 single engine helicopter, N422SH, sustained substantial damage when it impacted water while hovering near Bandera, Texas. The commercial helicopter pilot and his passenger were not injured. Visual meteorological conditions prevailed and a flight plan was not filed for the animal herding flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 91. The local flight originated from a private ranch near Bandera, Texas, approximately 0820. In a written statement, the 2,216-hour pilot reported that after refueling at a private ranch, he and a passenger departed and "began a process of herding some exotic animals across an earthen dam to an open area for capture." One particular trophy exotic that they were trying to capture began to swim in a creek below, and "it was obvious that the animal was struggling to cross." The pilot then began to hover beside the animal to herd it out of the water and towards the bank. At this point, "the aircraft began to settle with power at a height of approximately six feet above the water." The pilot "applied forward cyclic and right pedal, along with a lower collective setting. The skid gear then settled into the water with forward motion, and the main rotors contacted the water." The helicopter sank in approximately six feet of water. A review of photographs taken after the accident revealed structural damage to the main rotor blades and the fuselage. According to the Federal Aviation Administration (FAA) Rotorcraft Flying Handbook, pages 11-5 to 11-7, Vortex Ring State (Settling with Power), "Vortex ring state describes an areodynamic condition where a helicopter may be in a vertical descent with up to maximum power applied, and little, or no cyclic authority. The term 'settling with power' comes from the fact that the helicopter keeps settling even though full engine power is applied. In a normal out-of-ground effect-hover, the helicopter is able to remain stationary by propelling a large mass of air down through the main rotor. Some of the air is recirculated near the tips of the blades, curling up from the bottom of the rotor system and rejoining the air entering the rotor from the top. However, when the helicopter begins to descend vertically, it settles into its own downwash, which greatly enlarges the tip vortices. In this vortex ring state, most of the power developed by the engine is wasted in accelerating the air in a doughnut pattern around the rotor. In addition, the helicopter may descend at a rate that exceeds the normal downward induced-flow rate of the inner blade sections. As a result, the airflow of the inner blade sections is upward relative to the disc. This produces a secondary vortex ring in addition to the normal tip-vortices. The secondary vortex ring is generated about the point on the blade where the airfoil changes from up to down. The result is an unsteady turbulent flow over a large area of the disc. Rotor efficiency is lost even though power is still being supplied from the engine." At 0745, the automated weather observing system at the Kerrville Municipal Airport (ERV), located approximately 20 nautical miles north of the accident site, reported no wind, scattered clouds at 12,000 feet, 10 statute miles visibility, temperature 52 degrees Fahrenheit, dew point 45 degrees Fahrenheit, and a barometric pressure setting of 30.08 inches of Mercury. ## Aircraft - Registration: [N422SH](https://openairdocs.org/deregistered/N422SH-2006-11-15), registration cancelled 2006-11-15, S/N 3604, built 2004 (OpenAirDocs) - Reported make and model: Robinson R22 - Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs) - Registry engine: [Lycoming O-360 series](https://openairdocs.org/engine/lycoming-o-360-series) (registry code 41575, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3604 - Airframe hours: 445 - Engines: Lycoming O-360-J2A 134 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 91 - Operator: Sendero Helicopters, Inc. - Registered owner: Sendero Helicopters, LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 12, 2005, 45 hours before - Departed: Bandera, TX - Airport: ERV, Kerrville Municipal Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: none; commercial; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 2,216 total, 2,013 in this make and model, 2,123 as pilot in command, 155 in the last 90 days, 78 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 0° at 0 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 45 °F - Altimeter: 30.07 inHg - Observed at: ERV ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20050427006199A](https://openairdocs.org/incident/20050427006199A), Apr 27, 2005: Robsin R22, Bandera, TX, Destroyed. (-23) At approximately 0830 CST on April 27, 2005, a Robinson R22 helicopter with a commercial pilot and passenger were herding deer on a private ranch in… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.